Radio frequency identification (RFID) system uses radio waves to transmit identification data such that the user can obtain required data wirelessly. RFID system includes a radio frequency identification (RFID) tag and a reader.
An RFID tag is mainly constituted by an RFID chip and a tag antenna. The RFID chip of the RFID tag stores corresponding identification data such as product name, supplier, and replenish data. The tag antenna of the RFID tag will perform wireless transmission between the reader, to obtain required data.
The cost of the RFID tag is mainly caused by the RFID chip, the metal usage in the tag antenna and the tag manufacturing process (such as package). The cost of the RFID tag will be cut down if the metal usage in the RFID tag antenna can be reduced.
Let a commonly RFID tag be taken for example. Its size is normally 1×4 inches (25 mm×100 mm), its length is smaller than ½ times of the wavelength of UHF frequency band (900 MHz: 135 mm), the metal coverage rate is about 20%˜80% of the total area, and the metal coverage rate of the tag antenna is an important factor that makes the tag cost difficult to be reduced.
Of the current technologies, the RFID tag antenna normally adopts the meandering design to compensate the antenna electric length. As the tag antennas adopt a larger metal plane with a larger coverage rate, the material and cost of the tag can hardly be reduced further.
Thus, the application provides an RFID tag.